Wildlife Trust Living Landscape Herritage SACs, SPAs & Reserve Scheme Coast Ramsar sites LOCATIONS CARDIFF-WESTON SHOOTS BEACHLEY WELSH GROUNDS BRIDGWATER BAY Bristol Weston-super-Mare Minehead Exmoor National Park Foreword The University of Exeter is known for world leading research into ‘Climate Change and Sustainable Futures’ and has recently established the Environment and Sustainability Institute in Cornwall to further research in environmental sustainability. In addition, the University is committed to developing sustainability literate graduates. In 2010, the Big Dilemmas Project was launched with the view to develop a better understanding of the sustainability dilemmas that society is trying to grapple with. Twenty of the brightest students from across the University were selected to form a think-tank. Working with stakeholders and lead academics., they focused on the theme ‘ The Future of Renewable Energy in the UK’ and drew lessons from the developments of the Severn Estuary tidal energy schemes. Under the previous Government five different constructions for energy generation were evaluated. Although the scheme has been shelved for now, it might be resurrected in the future in one shape or another. This makes it an interesting case study for policy makers, investors and activists alike. The think-tank researched challenges around energy security, protection of biodiversity, public engagement and economics. In this pamphlet the students are presenting their conclusions* and are offering some insightful propositions on how to approach complex sustainability dilemmas. I echo Martin Wright’s (Forum for the Future) comment at the final Big Dilemmas symposium: “If we want to move towards a sustainable society, we need to win hearts and minds. We need to change the narrative and promote optimism, entrepreneurship and innovation. The students who are participating in this project are doing just that.” Harriet Sjerps-Jones, Sustainability Curriculum Development Manager, University of Exeter, 2011 Sources have been referenced where possible and have been verified by the students to their best ability, however the University of Exeter can not take any responsibility for the validity of the data quoted in this publication Introduction When the Department of Energy and Climate Changed announced on October 18th last year that the Severn Tidal Barrage Project would be shelved, it put another twist in the story of harnessing energy from the Severn Estuary. Since as early as 1925 (The Ecologist, 2010), proposals have been made to generate predictable, renewable electricity at the Estuary – the latest of which generating up to 5% of UK electricity demand (DECC, 2010). It must be questioned, however, why so many attempts have failed to get the go ahead. If looked at from an engineering perspective, the project is an exciting one; even before electricity was proposed, there was a barrage proposed to produce a large shipping harbour, road and railway transport and an increased level of flood protection (Caine, 1995). The barrage, shown below, would certainly have been an impressive sight and celebration of engineering. Since then, the potential for large scale electricity generation has made it popular to the engineering world. Looking at major projects from one perspective has never been satisfactory. For the Severn, this was highlighted by shelving of the project on economic reasons seven times between 1925 and 1981. However, an interdisciplinary approach is ever more important, particularly in issues relating to energy and climate change. A move towards a more holistic approach with the Severn Barrage Project was taken in 1984 and 1989, when the environmental impacts of such a project were taken far more seriously (DECC, 2010). With The Severn Estuary being subject to conservation designations on both a national and international scale, the environmental impact of a barrage is a huge consideration. With intertidal mudflats and sandflats extending to 23,000ha in the area being just one of the concerns, the barrage proposals have brought about conflict as to the nature and extent of change and damage it would bring about. Engineering, economics and ecology are not where the issues surrounding the barrage end. Public acceptance, integration to the electricity transmission network, shipping and the role of policy are just some of the many factors which much be considered for the project. These are the issues that organisations such as Corlan Hafren are faced with. An industry consortium formed after the October announcement by Government, Corlan Hafren are proposing that private sector money could finance the project (Corlan Hafren, 2011). This clearly won’t be the last that is heard of the Severn Tidal Barrage. With the future proposals likely to need interdisciplinary approaches and analysis, it is hoped that the approach taken by the Think Tank in this report can provide a useful overview and insight to the lessons that can be learned from the story so far. Laura Daniels References: Caine, B. (1995). Thomas Fulljames, 1808 - 1874: surveyor, architect and civil engineer. Available: http://www2.glos. ac.uk/bgas/tbgas/v113/bg113007.pdf. Last accessed 25/05/2011. Corlan Hafren. (2011). Welcome to Corlan Hafren. Available: http://www.corlanhafren.co.uk/. Last accessed 25/05/2011. DECC. (2010). Additional Background Information. Available: http://www.decc.gov.uk/en/content/cms/what_we_do/uk_ supply/energy_mix/renewable/severn_tidal_power/feasibility/background/background.aspx. Last accessed 25/05/2011. The Ecologist. (2010). Severn Barrage Faces Economic rather than Environmental Hurdles . Available: http://www. theecologist.org/News/news_analysis/522790/severn_barrage_faces_economic_rather_than_environmental_hurdles. html. Last accessed 25/05/2011. Energy Policy, Renewable Energy & the Business Case The interest in building the Severn Barrage stems from the pressing concerns surrounding climate change. To tackle this looming threat the government has implemented targets to reduce greenhouse gas emissions by 80% by 2050 and to increase the amount of energy generated from renewable sources to 15% by 2020. This in effect means 30% of electricity generated in the UK has to come from renewable sources by 2020 and the entire electricity system needs to be effectively de-carbonised by 2030. To address these challenges the government has published a number of white papers in recent years. The key objectives outlined in these policy prescriptions are to decarbonise the economy at an affordable price whilst maintaining acceptable levels of energy security. Barrage Pros The Severn Barrage has the potential to play an important role in the transition to a low carbon economy as it represents a semi-reliable indigenous source of zero carbon electricity. In the long term it would help to reduce both the nation’s carbon emissions and the country’s dependence on imported fossil fuels. The power generated could theoretically provide up to 5% of the country’s electricity needs. Barrage Cons The barrage is a huge investment and the twelve year construction timeline makes it unattractive for politicians looking to make a dent on the 2020. Due to its size it could potentially soak up a lot of government resources and crowd out other renewable technologies struggling to find their way into the electricity generating mix. Finally, one of the major worries is that the barrage could cause significant and potentially irreversible environmental damage. KEY INDICATORS OF BARRAGE SCHEME Details of the Barrage Figure 1 shows the Cardiff-Weston barrage proposal is the largest of the options being considered and would 23.2 4.7 3.5 6.8 12.0 cost approximately £23.2bn. Once built the barrage (34.3) (7.0) (5.1) 23.234.3 7.0 5.1 10.1 17.7 would generate 15.6 terawatt hours of electricity per year over its one hundred and fifty year operating lifetime. CAPITAL COST (£BN) (OPTIMISM BIAS INCLUDED) An indication of how the barrage compares with other VS technologies in terms electricity produced and carbon ENERGY GENERATED (TERRAWATT HOURS PER YEAR) saved can be seen in figure 2. Does it represent a good investment? 15.6 2.7 1.2 2.6 6.2 In order to get an idea as to whether the barrage represents a shrewd investment the Levelised Cost Of Electricity (LCOE) can be used to compare how the barrage compares to other low carbon generation technologies. Levelised costing calculates in current terms LOCATIONS all capital, fuel and operating and maintenance costs CARDIFF-WESTON associated with the generating plant over its lifetime and Figure 1: Estimated costs SHOOTS and electricity generated for BEACHLEY divides the total cost by the estimated output in kWh over the different Severn Barrage WELSH GROUNDS the lifetime of the plant. It can also be interpreted as the proposals BRIDGWATER BAY constant level of revenue needed each year to recover all LARGEST BARRAGE equates to LARGEST BARRAGE equates to 2100 WINDTURBINES 2100 WINDTURBINES = 10 WIND TURBINES = 10 WIND TURBINES This information has been produced using the This information has been produced using the figures found for 1 Offshore 3MW wind turbine, figures found for 1 Offshore 3MW wind turbine, which prodcues 0.0074TWh per year, meaning the barrage’s could produce the equivelent of which prodcues 0.0074TWh per year, meaning between 162 and 210 offshore wind turbines. the barrage’s could produce the equivelent of between 162 and 210 offshore wind turbines. KEY INDICATORS OF BARRAGE SCHEME Data source: Severn Tidal Power. Feasibility Study Conclusions and Summary Report. October 2010. Figure 2 http://www.decc.gov.uk/assets/decc/ the expenses over the life of a power plant. The advantage KEY INDICATORS OF BARRAGE SCHEME of LCOE is that it allows the comparison of various LEVELISED COSTS – INVESTOR (10%) LEVELISED COSTS – SOCIAL (3.5%) technologies of unequal life times and capacities as shown £/MEGAWATT HOUR. VS OPTIMISM BIAS INCLUDED in Figure 3. The graph shows that the levelised cost of the OPTIMISM BIAS INCLUDED barrage, when considered from an investor’s perspective, is significantly higher than the other low carbon technologies.